This project has the overall objective of using survey research data to help answer a number of research questions about the mental health service system. A preexisting data set containing information on a representative national sample of psychiatrists, primary care physicians, psychologists, and social workers will be used. Among the most important questions are the following: (1) Services demand and supply: What is the nature of and what factors predict consumer demand for and provider supply of mental health services? (2) Services benefits: What mental health benefits (i.e., changes in mental health status as a function of provider work) are derived from different provider groups, and what factors predict benefits and benefit differences? (3) Provider effort: How does effort (e.g., hours per patient per work month per episode of disorder) vary across provider groups and across mental disorders and what factors predict effort and effort differences? (4) Provider supply: How does the supply of provider groups vary across geographic regions, and what factors predict supply differences? (5) Distribution of providers according to practice setting: What is the nature of and what factors predict the way in which different categories of providers are distributed (1) according to settings with different interworking relationships among providers and (2) according to the setting's sector (e.g., public or private)? The detailed analysis plan contained in the body of the proposal describes the proposed use of a variety of standard and high sophisticated statistical procedures appropriate for the data analysis relevant to each of the above mentioned questions. Answers to the above question areas will be useful for both the understanding and the possible alteration of the following major public policy areas: (1) number and mix of providers required, (2) nature of mental health insurance, (3) geographic distribution of providers, (4) impact of regulation on provider competition, and (5) provider substitution.